Intestinal Ultrasound in Inflammatory Bowel Disease: Monitoring Inflammation and Treatment Response

Inflammatory bowel disease (IBD), including Crohn's disease and Ulcerative Colitis, is a chronic immune-mediated condition that requires long-term monitoring to prevent disease progression and complications. The adoption of treat-to-target strategies has highlighted the limitations of symptom-based assessment and the need for objective tools to evaluate both mucosal and transmural inflammation. In this setting, cross-sectional imaging has gained relevance, and intestinal ultrasound (IUS) has emerged as a noninvasive point-of-care modality for disease monitoring.

As the evidence of IUS in the monitoring of IBD continues to expand, we provided a comprehensive overview of its clinical applications and supporting evidence.This narrative review summarizes the current evidence regarding the role of IUS in monitoring therapeutic response in IBD including results of retrospective and prospective studies and meta-analyses.

The IUS demonstrates high diagnostic accuracy in assessing inflammatory activity in both Crohn's disease and ulcerative colitis, with strong correlations with endoscopic and biochemical markers. In Crohn's disease, IUS enables early detection of treatment response to biologic and small-molecule therapies, assessment of transmural healing, and identification of complications such as strictures, fistulas, and abscesses. In ulcerative colitis, IUS has been shown to predict endoscopic remission, clinical response, and long-term outcomes, including the risk of colectomy. Early ultrasound assessment is also valuable in acute severe ulcerative colitis, identifying corticosteroid responses, and the need for rescue therapy or surgery. Several ultrasound-based scoring systems have been proposed; however, only a limited number have undergone robust external validation, and definitions of response and remission remain heterogeneous. Overall, IUS represents a valuable tool for personalized disease monitoring, although wider standardization using validated scores is required for broader implementation.